Sectional mold for tire casings



Sept.. 28, 1943. H. L. BAKER 2330329 SECTIONAL MOLD FOR TIRE CASINGSFiled Aug. 50. 1940 2 Sheets-Sheet 1 mmm):

INVENTOR HHZOLD L. BAKER ATTORNEYS H. L.. BAKER SECTIONAL MOLD FOR TIRECASINGS sm., 2a, mm

Filed Aug. 50, 1940 2 Sheets-Sheet 2 2G INVENTOR HAROLD L. BQKER iig.. 7f2 BY 1 mx/@M ATTORNEYS Patented Sept. 28, 1943 UNITED STA'ESI PAT E NTOF'FIC E? 2,330,329 i snoroNaL Moro Foie TIRE casinos narcis L. Baker,oakland, Calif.

llrmlicaton August 30, 1940, SerialNo; 354,811

(ci. 1s1si 4- Claims.

This invention relates to molds for tire casings, the illustrations anddescription being-` speciiically directed to a sectional mold in whicha` section only of a tire casing is to be receivedrfor repairing.. y l

One of the objects of the invention isa-n1 irnproved mold of the abovecharacter, constructed' from sheet steel, such, for example, as boileriree from latent defects as commonly exist inr cast molds, and whichimproved Inoldlfis substantially free from porosity, warpage,susceptibility to injury in handling and in use,v and insures a moreuniform and more efficient vulcani Zationof the tire than'l'ieretofore.

Other objects and advantages will appear in the description anddrawings.

In the drawings, Fig. 1 is a side elevational View of my improved mold.

Fig.. 2 is a longitudinal sectional View of the mold of Fig. 1.

Fig.. 3y is a cross-sectional View taken along line 3--3 of Fig. 2, witha tire casing thereinA indioated in dotted line.-

4 is perspective view` of one of the improved, removable, side-Wallplates that consti'- lutes a part of the mold, a portion of the platevduring thel development thereof being indicated in dotted line at oneend of the plate, and Fig, 4a

is ra reducedI size elevational View of a slightly' d-iierent structurein the side Wall plate. n

Fig. 5 is a cross-sectional view illustrating a mold for use inrepairing several tire casings simultaneously, if desired, and whichview also shows means for adjusting the molds to various sized tirecasings, which latter means is equally adaptable' for use in the singlemold illustrated tiresv or sections thereof,. are generallythe sameinsofar as their mode of operation. Each has a steam chamber ,inV whichsteammay` be introduced from a source of supplyy or Water in saidchamber may be converted into. steaml by any desirable source ci heat.Side.wallfpl'a'tesi a tread,y plate" and a bead plate arerconvention'atelements of"a=` sectional mold'.` Acon'ventional airbag islfitted'4 intothe casing at the-.section t@ be repaired andi when the casing with theair bag therein iseinth'e mold', together with relatively plastic rubberproperlyipositioned to elect' a repair,y the: steam in' the steamychamber heatsthe side plates, tread plate, etc. and: the vulcanizationof the rubber" at the section is accomplished in. theusual.'man.`

ner for restoring the injuredpart ofthe' casingt'y its normal.condition'.`

Heretofera sectional` moldsihave been. cast. inv various forms.

thereof., but in each of the molds there: is anlenif` closedv steamchamber that extends acrossfthe. tread of the tire' casing and.@verbo-th' sidewalls, thevinner walls of which areV adjacent the tire..`but which are generally.' spacedc from-.the tire: cas:` ingby removableside. wall plates and a tread' plate.

The above described.V conventional molds: arefpractically impossib-letonredueewith th'efassur.- aneeofuniformst-rength inthe walls of the steamChamber, due te @wecken-therein. arid-'t varyf ing thicknesses im1 saidWalls.: Duey to.: the steam; pressure in Said steamL ehamber, theseWeaknesses have not infrequently resulted dangers"` ous explosions thathavebeenfatal totors, or else have maimed., crippledor; insured. theoperators to various degrees. Also @est moldear-e generally porousto agreater or lesser degree.- dus.

to imperfections and tothe character of the metal resulting many timesma dry boiler er mold', which. means that the mold or` boiler tubes 0.11both must be replaced.

Thus vtar, attempts to overcome tl'rese,l oniezcf.

operators to give the' public the convenience' oli" making quick andjeffective' repairs at any' costi. and the excessive costs of the moldstolarge co cerns has onlyv enabled'them torenderth'epuol f the lserv-icelof'repairs, but at `a cost t'l'iatis'ex?V cessi-ve when the cost of newtires is-considered.

Some molds' arev inseparable secztions forfinsertion of the casing and.for' release.

Costs 0f casi? molds dll@ t0 .the labor @este and to te expensedmaterials h'as heretofore been far'too great 1,39 enable mkl'llf.

My invention overcomes the above objections, and others, which occurquite commonly in cast molds, such as unequal heat transfer in the moldwalls; warpage; the tendency of the cast molds to easily break, etc. Itis not unusual in large cast molds to nd that there is a variation up toF. in the heat transfer efficiency at various points in the mold walls.When it is considered that correct vulcanization requires application ofa substantially uniform temperature at between 286" F. and 293 F., thevital importance of insuring transfer of a uniform amount of heat at allpoints in the mold walls adjacent the tire section, is apparent.

The use of boiler plate, or sheet steel in applicants mold also providesa mold free from any latent weaknesses or defects, and capable ofwithstanding pressures far in excess of a cast mold, and pressures farin excess of that employed in vulcanizing. Heretofore the need for astrong, cheap, and reliable sectional mold has been recognized in thetrade, but the attempts of which I am aware, for producing such mold,have been restricted to attempts to cheapen cast mold structure, thecheapest of which molds is far in excess of the cost of producing mymold.

In detail, the main body of my mold, as illustrated in Figs. 1 to 3,inclusive, comprises a central, elongated channel, in which the sidewalls are indicated at I, and the bottom at 2 (Fig. 3). This channel maybe stamped from a single sheet of rolled steel, such as boiler plate.The bottom 2 of said channel and the line of bend defining theconnecting edges ofthe bottom and side walls, are arcuate,longitudinally of the channel, with the concave side of the bottomfacing the space between the side walls.

Within the aforesaid channel the tire section to be repaired isreceived, hence the curvature of said bottom generally conforms to thecircumferential curvature of said tire section. However, the use ofremovable side wall plates and a tread plate, and filter plates, as willlater` be described, enables the use of the mold for various sized tirecasings and provides a support for the tire casing that conforms to theouter contour of the tire transversely thereof.

The walls of the channel also comprise walls of a steam chamber 3, theremaining walls of which chamber comprise angle strips, the short legs4, 4 of which are welded together at 5 at a point centrally below bottom2, and which legs extend longitudinally of said bottom, but spacedtherefrom, curving upwardly at their ends to join the ends of saidbottom to which said ends are welded. The longer legs 6, 6' of saidangle strips extend upwardly in opposed relation and are spacedoutwardly of the sides I of the channel. The upper margins I of legs 6,6 are pressed or bent inwardly, or to the same sides of the legs as thelegs 4, 4', and the free edges engage the sides along lines slightlyspaced below the upper free edges of the latter for welding 'I' alongthe line of engagement and between the upper edges of the margins 'I andfree edges of sides I. Likewise the margins Il at the ends of legs 6, 6and the corners of said legs at the adjacent ends of margins 'I, 3 areturned inwardly the same as margins 'I and are welded to sides I in thesame manner as described for margins "I, thus providing the steamcharnber 3 between legs 4, 4 and bottom 2, and be; tween sides I andlegs 6, 6'. The angle strips providing legs 4, 4', 6, G', when weldedtogether at 5, thus constitute an outer channel in which the innerchannel is carried.

In the following description, and in the claims, the term inner channelwherever used, refers to the channel formed by side walls I, and bottom2, and the term outer channel refers to the outer walls of the housing,as above dcscribed.

The `tread plate illustrated in Figs. 2, 3, is made yup of threelongitudinally extending, parallel, separable sections, each beingcurved longitudinally on its bottom side to correspond to thelongitudinal curve of bottom 2, for fitting thereagainst.

The central section 9 of the tread plate assembly is substantially flatwhile the two outermost sections I0 are curved in cross-section on theirupwardly facing sides, when the plates are supported on bottom 2 to formupwardly curved continuations of the substantially flat upper surface ofthe central section. When these sections are assembled in the mold, theyvirtually form a single tread plate the upper surface of which,corresponds in contour transversely thereof, to the desired tread andshoulder shape of the tire casing. referably these sections are ofaluminum, and the provision of the three pieces enables adjustment tovarious width tire treads, which is accomplished by substitution ofsections 9 of different widths, as desired.

In some instances, a tread plate II, as indicated in the left handcavity in Fig. 5, which tread plate is merely a strip of sheet metal inwhich the longitudinally extending margins have been bent upwardly todivergently extending relation as indicated in Fig. 7, after which theouter sides of the upwardly bent margins as designated in dotted line atII', are ground off to provide outer vertical surfaces resulting intapered margins I2. This is a simple, cheap and new form of tread plateparticularly suitable for smaller sized tires.

The side wall plates of my mold are best indicated in Figs. 3, 4 and aregenerally designated I3. There is a pair of these plates, each beingadapted to substantially cover one of the inner sides of the innerchannel of the form. Thus each of these plates is generally fanshaped.In Fig. 4 the side therein illustrated is the side that is supportedagainst one of the sides I of the inner channel. Each of these side wallplates is stamped from a single sheet of metal of rapid heatconductivity, such as aluminum. The longitudinal edges that extendlongitudinally of the inner channel are preferably parallel and curvedabout substantially the same radius as the bottom 2. The longer or lowercurved edge of each plate I3 terminates in a free edge, but the marginof each plate along its upper, or shorter edge, is bent over to form aflange I4, and from the juncture of such flange toward thefree loweredge, each plate is curved as at I5, to conform to the outer contour ofthe bead portions of the tire I5 (indicated in dotted lines in Figs. 3,5). This curvature preferably extends partially up the side walls of thetire so that a tire held between said side wall plates is supported inits proper shape by reason of the curvature of the plates I3.

From the point where said curvature l5 ends, the plates I3extend'substantially flat to the outer lower free edges thereof.

The margins I4 forming the flanges, as above described, are preferablyformed at each of their ends, before bending, with ears or longitudinalproections' t6), indicated in dottedlin'e-in ligA` One` of the.longitudinali edges `of eachearl iscurvedi to correspond' tothecurvature I5, while the opposite longitudinal edge isinstraightexltensionof the free longitudinally extending edgeof the angeIii. Thus when the flanges are formed, andl ears Ilare bent over, thecurved edges of the ears will fol-low the curved end4 edges of thecurved portion |15, and the' straight edges of the ears will be planarwith the straight portion of the plate IS. The corresponding' curvededges of plate I3v and ears I6 are then welded together and functionV asbraces as well as closures at the endsv of the plates i3, when theplates are" fitted in the inner channel of the mold, andi said`r earsalso act' toV conduct heat to the side wall` plates. f

Relatively wide ribs H f oi* aluminum corresponding 'generally in shapeto the earsl IB', may be'weld'ed to the plates I 3 adjacent anges likesindicated" in Fig. 4, to reinforce thel curved portionsk t5V of theplates as well as to function' as heat transfer means for rapidlyconducting heat from theA sides I of the inner channel to the tirecasing. s f

The plates I3 are positioned in the inner' crran'` nel, with their lowermargins opposite nanges I4 disposedY between the lateral o-uter sides'of-V the sections III' ofthe tread plate, Vand the flat sides 'of theplatesY I3V extending away from said lower" margins restY flat againstthe innerV sides of" the innerv channel while the curved portions I5Yadjac'ent flanges M extend inwardly toward each other across said innerchannel. The ribs Il, and free edges of iiange 4 and ears d5 rest-ragainst the inner'sides of said inner channel. Practical'- ly all of theside plates over that area .ofthe-'tire where the repairis eilectedv isiiatagainst' the sides I'of the inner channel.

Assuming the tire section is in the inner channel', as indicated in Fig.3, and an air bag is in the casing; it will be seen that plates' I3' maybe elevated4 or lowered, tol the correctt height forl conforming to thetransverse contourof theouter side ofthe tire, at and adjacent the beadof thel latter.-

vThe bead plate E8, which extends longitudinally of the inner chan-nel,is then fitted across the radially facing sides of the tire beadsi and"Yover -the anges It. This platel is. about thewidth of the channel,andfextendsfrom end to end of the anges lli, and so may be raisedlorlowered between sides I, .as desired. The-bead plate I8 carries anadjustingscrew I 9i, rotatably secured to said plate in a bearing 2B andthread-l` edly extends upwardly through athreaded blocky 2.I.thatsupports a pair of parallel bars` 22 at opposite sides thereof. Bars 22extend transverselyacross the inner channel and the opposite `ends. ofthe bars extend past opposite sides. of bolts 23. and between upper andlowe-r adjusting nutsr 24on each of said bolts. The bolts may be weldedto opposite outer sides of the inner channel, as, indicated in Fig. 5,or they maybe the endsof a stirrup bolt that extends below the innerchannel asindicated on Fig. 2. Of course, in any case,v suitable weldingseals the openings in margins I` through which the bolts passupwardly totheir positions between the opposite ends of the pair of bars. It isreadily seen that by turning Screw I9, which is provided with a squareupper end, the bead plate-may be raised or lowered ,accorde ingtowhichway-it is turned when the nuts 24 are adjusted to lock the ends of bars22v there,- between-oneach of the bolts 23. y Also uponrel.-

moval ofthe .uppermost of nuts 24, th'eltread platemay bereadily removedfrom. the mold andi the'tir'e: is their free for removal, as. are thelside wallv plates I3.

In. the; multiple cavity. mold. illustrated: in Fig'. 5,.A

generally the same. constructionl is followed as in. Figs; 1l to 3'. Theouter kchannel hasltheleg's: 28,. 26 thereof, that. correspond inposition. to legsl 4, 4 of Fig'. 3, which. are. lengthened: to enablere*- ception' of a pair o'r more of inner channelsbetween the legs E?,6B. These legs-2li; 255.."are weld'- ed. together a't 5,- as alreadydescribed for legs1 6, 6i. Also, the inner channels are formedwithi'langes 21. on their adij'acentsides l", which'v flanges. arewelded together, anda central bolt Z'Biextends upwardly between the twofcllannels.y andbetweenbars 2.2', which latter bars; correspond in. func#tion .to bars 22. of Fig. 32,. exceptthat.. bars 22'/ exi tend acrossboth of the inner channels. Screws. I9 are securedto beadf plates- I`8that are respectively disposed in eachV inner channel,` which: screws'thread'e'dly pass: throughr blocks 2l as 3. Bolts 23 welded to the.outermost sides of the' inner channels extendfbetween7 theend's oi? thepair ofr bars. 2.2." and. pairs of. nuts. 24! oir-s bolts 23 and on bolt218, function:` the same: asnuts 2i. Spacers 2liv welded to the innerchan nels at their lower adjacent sides function., to;-A gether withflanges 21, to secure the inner: chan nels in spaced relation. l

The bottoms 2 of theinner channels Fig; are not stamped from the samestrip o metalen: sides I, I', but are merely longitudinally curved'strips` that i'lt` at their oppositelongitud-i-nallyv extending margins.across the` lower edges sepa-- rate side plates. I', I "and welding.,indicated at W` between the free longitudinal edges of said? bottitomand the edges ofV sides I1, I securethe-y bot-VV toms 2 to said sidesI, Ii. This form of con: struction is often preferable where largepresses-n are not availableA for stamping the innerchannel as one piece.Of coursethe lower marginsoii the sidesl., I may extend past thelongitudinal.;

edges of bottom 2 for welding below bottoms 2 rather than at the sidesof the sides I, I1', if' dem sired.

/ Heretofore the methods employed forr adjusting molds to various sized:tires has necessitatedthe use oi many relativelyV expensiveaccessories.. With my invention, however;. substantially all; that isrequired are metal plates that are readily and quickly stamped out of asheet of.` metal. The left hand inner channel illustrated in.- 5 isadjusted to receive a relatively small. sized. tire casing by thelemployment of. as many, dat.. fan-shaped plates 3B asmay bereduired. ateach.- lateral side I of the channel to reduce the width; of the moldsuliiciently to properly receive the tire when side wall plates` 3l,corresponding. in. structure to side wall plates i3 (butshaped forthesinaller sizedtire) are supported against the innermost of plates 3l.N aturelly the tread plate.` Il, already described, mustk be of thecorrect;` contour for the smaller tirecasing. Thev right. hand innerchannel of Fig. 5 is adjusted.V for a. larger sized tire casing, inwhich only one flat. plate 3| is used between the side wall plates 535.By dropping out all of the nat plates 36, Si, and. using the arrangementshown inFig. 3, the innerr channels of Fig. 5 may receive` a stilllarger tire .f

casing. In. eachinstance the tread plate may be raised or loweredbetween: the sidesl ofthe: inner channels. Of course the tread plate`assembly of Fig. 3 or the treadplatesfof Fig. 5 may: besubstituted` oneyfor. the other, as desired.,

In the mold illustrated in Fig. 6 the inner channel is identical instructure with the inner channels illustrated in Fig. 5, having sidesI', a bottom 2. Insteadof the outer channel being in the form of anglestrips Welded together, I provide a pair of plates 33 spaced at oppositeouter sides of the inner channel, which plates have inturned uppermargins 1', and end margins 8', that are welded to the upper edges ofsides and to the end edges thereof, in the same manner as described forthe molds of Figs. 3 and 5. These plates 33, however, extend directlydownward with legs 34 at their ends, and a plate 35'below bottom 2 iswelded at its edges to the inner sides of said plates 33 as at W to formthe bottom of the outer channel. The mold itself is therefore seen to`form inner and outer channels with a steam chamber therebetween.

In all of the molds illustrated, air release means for releasing trappedair in the steam cavities is provided, as best indicated in Fig. 3,which air release means comprises relatively small pipes 31 secured byspot welds or otherwise to the sides of the inner channels within saidsteam cavity at the uppermost portion thereof. These pipes are open attheir ends at 31 at the uppermost points in said steam chamber. At oneof their corresponding ends, the pipes 31 extend downwardly to belowbottoms 2 (or 2'), as at 31" where they are connected by a cross pipe inwhich is a T fitting with the leg thereof extending through the bottomof the outer channel at one end thereof to a manual relief valve 38.This arrangement eliminates the necessity for four or more valves nowrequired in single or multiple cavity molds, and the valve 38 is in aposition where it is not likely to be struck and injured or broken off,as is common in conventional molds.

A thermometer 39 is secured to one side of the outer channel of eachmold, and an automatic pressure relief valve @El is also provided.

In instances where a steam boiler produces steam for the mold, a valvedinlet 4I and valved steam outlet 42 is provided (Fig. 1) or the outletmay be closed and water injected to a level below bottoms 2 (or 2'), andthereafter gas burners 42, or any other source of heat, such aselectricity, may be employed to convert the water into steam.

In the form of invention shown in Figs. 1, V2, 3 or 5, any suitable legsL (Fig. l) may be attached to the mold or may detachably support themold, if desired or the mold may be supported in a cabinet or otherframe, at a suitable height, no specific claim to the form ofsuch legs,cabinet or frame being made, such supporting means merely constituting asupport for the mold.

The view shown in Fig. Lla is of a side wall plate that is particularlysuited for bead repairs, where it is essential that heat be conducted tothe head portions ofthe casing. This side wall plate itself issubstantially the same as that shown in Fig. 4, but instead of the ribsl1 in the latter, I provide relatively thin sheet metal ribs l1' eachprovided with an ear l1 along the outer longitudinal edge thereof. Theseears extend toward each other and the space between the ribs is thenlled with molten metal 50 of any suitable kind, such as lead, babbitt,alu-` minum, or an alloy. Or where it is desirable to extend the moltenmetal to the ends of the plate, the end members i6', which correspond tomembers I6 of Fig. 4, have ears I6 that function the same as ears I1",for retaining the molten metal 50, 5| in position. The outer side of themolten metal, after cooling, is surfaced to be ush with the flat portionof the plate extending away from the outer ends of the ribs or endmembers.

Having described my invention, I claim:

1. In a cavity vulcanizer for pneumatic tire casings; a mold comprisinga channel having a iiat bottom Wall curved longitudinally of saidchannel, and flat, parallel opposed side walls extending upwardly fromsaid bottom wall at substantially right angles thereto; a tread filleron said bottom wall formed with two opposite edge surfaces adjacent saidside walls parallel with said side walls; a pair of opposed side plateswithin said channel with the sides thereof that are respectivelyadjacent said side walls being parallel with said side walls; the saidside plates being slidable parallel to said side walls and the opposedsurfaces of said side plates along their lower edges being in slidableengagement with said edge surfaces whereby said side plates may be movedto various positions toward and away from said bottom wall whilemaintaining slidable engagement with said side walls and said edgesurfaces; the opposed surfaces of said side plates along their upperedges being of a contour conforming to the contour of the axiallyoutwardly facing sides of the bead portion of a tire casing and thevertical width of said side plates being arranged and adapted tocompletely extend from the radially facing sides of such bead portion ofa casing to be positioned in said channel between said side platesacross the sides of such casing and a portion of the said edge surfacesof said tread filler.

2. In a cavity vulcanizer for pneumatic tire casings; a mold comprisinga channel having a flat, horizontally disposed bottom wall curvedlongitudinally of said channel, and opposed side walls extendingvertically upwardly from said bottom wall; the opposed surfaces of saidside walls being flat for their entire vertical widths and parallel toeach other and extending in planes at right angles to the plane of theflat upper surface of said bottom wall; vertically movable side platesrespectively positioned adjacent the opposed surfaces of said sidewalls; a horizontally disposed top plate extending between said sidewalls and over the upper edges of said side plates and having a ilatlower surface parallel with the upwardly facing surface of said bottomwall; means carried by said side walls supporting said top plate formovement of the latter toward and away from said upper edges of saidside plates; a tread filler on said bottom wall engaging the lowerportions of said side plates in slidable relationship with said sideplates for permitting vertical movement of the side plates relative toeach other and to said tread ller and side walls; and means on said sideplates formed integrally therewith arranged and adapted to snugly engagethe axially outwardly facing sides -only of the bead portions and sidewalls of a section of a tire casing to be positioned within said channelwhen the side walls of such section and the tread portion thereof arerespectively in engagement with the said plates and said tread ller.

3. A cavity vulcanizer comprising a pair of channels of sheet steeldisposed one within the other and with their adjacent opposite sides,and the bottoms thereof, respectively, in spaced opposed relationproviding the walls of a generally channel shaped steam chamber;supporting legs for said channels comprising extensions formedintegrally with the side walls of the outer channel of said pair, thebottom wall of said last mentioned channel being welded along twoopposite side edges thereof to said last mentioned side walls, andwelded at the opposite end edges to the corresponding end edges of thebottom wall of the inner channel of said pair; the marginal portions ofthe side walls of the outer channel of said pair extending angularlyinwardly toward each other along the end and upper edges of said latterchannel and welded along said edges to the corresponding marginalportions of the side walls of the inner channel of said pair; a topplate in the open side of the inner channel of said pair i top plate.

extending longitudinally of said channel and 4. In a construction asdefined in claim 3, the side walls of the inner channel of said pairbeing flat and parallel with each other; tread plates removablysupported on the bottom wall of said last mentioned channel havingopposite outer edge surfaces adjacent said latter side walls parallelwith each other and with the side walls of said latter channel; a pairof vertical side plates respectively positioned adjacent the oppositesides of the inner channel of said pair with the marginal portions alongtheir lower edges telescopically slidable between said edge surfaces ofsaid tread plates and said last mentioned side walls for verticalmovement relative to said tread plates, said side plates being normallyspaced along their lower edges from the bottom of said inner channel atvarious distances according to variations in the tires adapted to bepositioned within said latter channel and between said side plates.

HAROLD L. BAKER.

